The purpose of this study is 1) to determine if sodium fluoride can provide lifelong protection against dental caries and 2) to determine if sodium fluoride can furnish protection in successive generations of rats. Even though the benefits of fluoride treatment are widely recognized the mode of action is not fully understood. In this study the caries-protective action of fluoride will be examined by looking at the long range effects of fluoride. The results of this work will hopefully help us to further assess the effect of sodium fluoride as a lifelong protection against caries.